The 4 F's in psychology refer to the core survival responses controlled by the brain, particularly the amygdala and hypothalamus. They explain how humans and animals react to threats in their environment.

The main aspects of the 4 F's are:

• Fight – confronting a threat directly in an attempt to defend oneself or others.
• Flight – escaping or avoiding danger to ensure personal safety.
• Freeze – becoming still or immobilized when neither fighting nor fleeing is possible, often as a protective response.
• Fawn – attempting to appease or please the threat source to prevent harm, often through compliance or submission.

These responses are automatic survival mechanisms that activate under stress or perceived danger. Understanding the 4 F's helps psychologists and therapists explain trauma responses and design interventions for stress, anxiety, and PTSD.